<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>zig-zag-pattern</title>
    <style>
        .zig-zag {
            width: 240px;
            height: 240px;
            background-color: #fff;
            background-size: 60px 60px;
            background-repeat: repeat;
            background-position: -30px 0,-30px 0,0 0,0 0;
            background-image: linear-gradient(135deg, #000 25%,transparent 25%),
                              linear-gradient(225deg, #000 25%,transparent 25%),
                              linear-gradient(3155deg, #000 25%,transparent 25%),
                              linear-gradient(455deg, #000 25%,transparent 25%);
        }
    </style>
</head>
<body>
    <div class="zig-zag"></div>
</body>
</html>